ATLANTAWhile reduced-intensity conditioning allows hematopoietic stem cell transplant (HSCT) in older cancer patients who cannot tolerate standard conditioning regimens, only about one-third of such patients have an HLA-matched related donor available. For these patients, stem cells derived from unrelated umbilical cord blood (UCB) may provide a suitable and convenient alternative. Navneet Majhail, MD, of the University of Minnesota, reported good results with UCB transplants at ASH 2007 (abstract 331).
The trial included 90 patients older than age 55 undergoing reduced-intensity conditioning HSCT between 2000 and 2005. The most common diagnosis was acute myelogenous leukemia/myelodysplastic syndrome. Approximately half of the patients (n = 47) received stem cells from a matched related donor (6/6 HLA-matched).
The remaining 43 patients, who had no 5/6 or 6/6 HLA-matched related donor, received a UCB regimen consisting of total-body irradiation (200 cGy) and either cyclophosphamide/fludarabine (n = 69), busulfan/fludarabine (n = 16), or busulfan/cladribine (n = 5).
Matched related donor and UCB transplants produced equivalent outcomes with respect to the primary endpoint of progression-free survival (PFS), as well as secondary endpoints of overall survival, treatment-related mortality, and acute graft-vs-host disease (GVHD).
For the matched related donor and UCB groups, 3-year PFS was 34% and 30%, respectively (P = .98); 3-year overall survival was 43% and 34% (P = .57), and treatment-related mortality was 23% and 28% (P = .36).
Cumulative incidence of sustained donor engraftment, measured at 6 weeks, was 100% for matched related donor transplants vs 89% for UCB (P = .05).
There were no significant differences for the matched donor and UCB arms in the incidence of grade 2-4 acute GVHD (42% vs 49%) or treatment-related mortality at day 180 (23% vs 28%). UCB recipients had a significantly lower incidence of chronic GVHD at 1 year (40% vs 17%, P = .02).